Sludge dewatering filters have generally included screw and roller presses as well as filter screens, which typically require backwash cycles to prevent the filter from becoming clogged. Annular crossflow filters such as the McCutchen TriPhase Filter U.S. Pat. No. 7,757,866 (Jul. 20, 2010) feature an annular crossflow filter in at least one spinning disk, whose motion generates a shear lift effect which helps to keep the solids from clogging the filter. The faster the disk can spin, the greater will be the crossflow motion relative to the feed and the greater the shear lift effect. However, the centrifugal force from a rapidly spinning disk will make the feed move more rapidly outward across the filter surface, and reduce the time for the filtration to take place. While this approach can separate liquids, solids and gas phases, it cannot also at the same time separate a liquid oil phase. What is needed is a way to make best use of a shear lift effect for filtration from a spinning filter surface, with an increased residence time, and a simultaneous separation of solid, liquid, gas and oil phases.